河川津波発生時の弾力的な樋門操作による内水氾濫抑止対策に関する検討

抄録

The main aim of this report is to investigate the measure for controlling inside-levee inundation by flexible sluice gate operation in the event of tsunami in rivers. In order to prove the validation of our two-dimensional model, it is first applied to the simulation of the flood inundation in the Shiribetsu River by the 1993 Earthquake Tsunami off the Southwest coast of Hokkaido. Then it is used for predictions of tsunami run-up and subsequent inundation in both varying tsunami height and gate openness. It is shown that complete gate closure can increase the inundation risk of residential area particularly in the flooding time. A new sluice operation, namely, keeping a loophole of inside-levee discharge is proposed to resolve this problem. Numerical experiments in the targeted river sluice gate show the effectiveness of the measure for a key solution for inhibiting flooding for a certain period of time.